Caster for a chair



FIG. 1 is a left side, top and front perspective view of a caster for a chair showing my new design;

FIG. 2 is a front, top and right side perspective view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is top plan view thereof;

FIG. 5 is a rear elevational view thereof;

FIG. 6 is a bottom plan view thereof;

FIGS. 7 and 8 are respectively right and left side elevational views thereof; and

FIG. 9 is sectional view taken on the line A--A in FIG. 8. 

The ornamental design for caster for a chair, as shown and described. 